1. Technical Field
The present invention relates to power supplies, also known as power adapters and power converters. In particular, the invention concerns power supply equipment, including power adapters, cables, connectors and connector adapters (tips) which can provide an appropriate adapter identification signal, as well as DC power, to various types, brands and models of electronic devices.
2. Description of the Related Arts
Power adapters used to provide DC power to portable electronic devices, such as notebook computers, cellular telephones, PDAs, MP3 players and the like, are available to end users from two general sources. On the one hand, electronic device manufacturers often include a power adapter with the purchase of an electronic device. Such power adapters are typically configured to power only the corresponding type, brand and model of electronic device. On the other hand, companies specializing in power adapters often sell universal power adapters and associated equipment which can be utilized to power a variety of types, brands and models of electronic devices. U.S. Pat. No. 6,693,413 describes power adapter circuitry, cables, connectors and connector adapters (tips) used to provide the voltage, current and mechanical interface appropriate for a variety of electronic devices.
For reasons including device power management, some electronic devices require the reception of a data or identification signal, in addition to DC power, from a power adapter. Such signal may provide to the electronic device information such as an adapter manufacturer name or code, an adapter power rating and/or an adapter current rating. For example, the signal may be a character string (of logical “1s” and “0s”) which encodes the message, “Manufacturer A, 90 Watts”. Based on the presence of the identification signal, the electronic device recognizes that it is coupled to a compatible power adapter. Dependent on the power rating value, the electronic device may enable or disable certain functions. For example, the device may enable battery charging circuitry in response to a power rating value of 90 W or more, but disable battery charging in response to a power rating value of less than 90 W (see U.S. Pat. No. 7,868,486).
With respect to universal power adapters utilizing a variety of connector adapters (tips) to mechanically interface with a variety of electronic devices, U.S. Pat. No. 7,999,412 discloses placement of circuitry within the various tips to generate the data signal expected by a corresponding type, brand and model of electronic device. Placing the data signal generation circuitry within the tips has a cost disadvantage in that the circuitry must be included in each of the individual tips to be used for interfacing with an electronic device expecting a data signal. The cost factor impacts any such tips needed to replace lost or damaged tips, as well as such tips originally sold with the adapter.